AB0701 PERFORMANCE OF DRAFT 2022 ACR/EULAR CLASSIFICATION CRITERIA IN A TURKISH COHORT OF APL ANTIBODY POSITIVE PATIENTS
Authors: R. C. Kardaş, D. Yildirim, B. Özkiziltaş, I. Vasi, R. Duran, H. Karadeniz, A. Avanoglu Guler, A. Erden, H. Küçük, B. Göker, A. Tufan, M. A. Ozturk
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Revised Sapporo classification criteria is the most commonly used criteria set for the classification of antiphospholipid syndrome (APS) patients [1]. Since its revision in 2006, various other clinical and laboratory manifestations have been reported in the literature. Among these are livedo reticularis (racemosa), cutaneous ulcers, thrombocytopenia, cardiac, pulmonary and renal involvement [2]. In 2022 American College of Rheumatology Convergence meeting, new draft classification criteria have been presented [3]. <h3>Objectives</h3> Comparing the performance of the new draft classification criteria for antiphospholipid syndrome with the revised Sapporo criteria in a Turkish cohort of antiphospholipid antibody positive patients. <h3>Methods</h3> Patients with a positive antiphospholipid antibody (LAC, aCL IgM or IgG, aB2GPI IgM or IgG) followed since 2016 in our institution have been included. Demographic, clinical, laboratory and radiological features of the patients were recorded retrospectively. All parameters were evaluated with reference to the 2006 revised Sapporo and 2022 draft criteria. <h3>Results</h3> 40 patients were included our study. 80% (N=32) of the patients were female. Average age of the patients at diagnosis or first antibody positivity was 33.9 years. 27.5% of patients (N=11) were screened for hereditary thrombophilia, with only one patient having heterozygous factor V Leiden mutation. 37% of patients (N=13) had ever smoked prior to their inclusion in the cohort. 57.5% of patients (N=23) had secondary APS, 12.5% had primary APS, 30% had isolated antiphospholipid antibody positivity. Among the secondary APS patients, vast majority had SLE (N=20). 47,5% of the patients (N=19) had a history of vascular thrombosis. 16 patients had venous and 5 patients had arterial thrombosis. Among the 32 female patients, 62,5% (N=20) had an obstetric morbidity associated with APS. 20,5% of patients (N=8) had a skin finding consistent with APS, the most common one being livedo racemosa (N=7). 50% of patients had thrombocytopenia. 20% of patients (N=8) had developed autoimmune hemolytic anemia. Only a single patients had a history of catastrophic APS. 17,5% of cases (N=7) had a positive lupus anticoagulant. Most commonly positive aPL antibody was anti-cardiolipin IgG (55%, N=22), followed by anti-B2GP-I IgG (28%, N=11). 82% of patients (N=33) had a positive ANA test, 62,5% (N=25) had low C3 and C4. Overall, 42,5% (N=17) of patients fulfilled 2006 revised Sapporo criteria, whereas 40% (N=16) ultimately fulfilled the 2022 draft criteria for classification. There was a large level of agreement between the two criteria sets, with one patient not fulfilling 2006 criteria fulfilling 2022 criteria and two patients fulfilling 2022 criteria without fulfilling 2006 criteria. <h3>Conclusion</h3> Our cohort of patients had a high prevalence of thrombocytopenia, as well as a significant minority having livedo racemose and autoimmune thrombocytopenia. None of the patients with isolated aPL antibody positivity were classified as APS, despite many of the fulfilling the initial screening step of the draft criteria. Longer term follow-up of patients fulfilling 2022 screening criteria may yield additional information in the future. <h3>References</h3> [1]Miyakis S, Lockshin MD, Atsumi T, <i>et al.</i> International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). <i>J Thromb Haemost JTH</i> 2006;<b>4</b>:295–306. [2]Ugolini-Lopes MR, Criado PR, Parsi K, <i>et al.</i> Treatment of Non-criteria Manifestations in Antiphospholipid Syndrome. In: Erkan D, Lockshin MD, eds. <i>Antiphospholipid Syndrome: Current Research Highlights and Clinical Insights</i>. Cham:: Springer International Publishing 2017. 247–66. doi:10.1007/978-3-319-55442-6_13 [3]Jarrett K. Investigators unveil draft of new classification criteria for antiphospholipid syndrome. ACR Converg. Today. 2022.https://www.acrconvergencetoday.org/investigators-unveil-draft-of-new-classification-criteria-for-antiphospholipid-syndrome/ (accessed 15 Jan 2023). <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.